This invention relates to a knife, and more particularly to a type of knife for all the more common uses, from that of an item of cutlery to be used once and then thrown away, to that of a general kitchen knife.
The development of technology has seen relatively little change in the structure of knives for some centuries past. The greatest innovations are merely the introduction of stainless steel and serrated blades. In fact, recently, certain sophisticated knife blades have disappeared, and the available range has been reduced, because of the increasingly widespread introduction of slicing machines in the family kitchen. However, new requirements have arisen. Meals on journeys, in trains or aeroplanes, meals during meetings of employees or members of organizations, and meals in the open air all require for their proper comfort the provision of a set of cutlery which can be disposed of after use, and this in certain cases costs less than collecting and washing conventional cutlery.
This has led to the development of plastic cutlery to be disposed of after use, and provided in sealed packages to ensure their hygiene. However, plastic knives at present available for this use are not suitable for the functions which they are required to perform. Plastic is not suitable for knives in that it does not cut. It would be possible to manufacture knives of a special plastic offering a certain cutting power for a short period, but the cost would no longer be economical.
There are also many other uses for which it would be advantageous to provide a general knife with a metal cutting edge which is of immediate use and of low cost, of the same order as plastic knives. An example of such a use is where normal knives are easily broken or lost.
A clear idea of the supply and demand situation can be obtained from figures given for pure comparison purposes. If it is assumed that a general knife with a metal blade costs one dollar, then it can be assumed that a plastic disposable knife would cost about one cent. There is no knife of an intermediate cost, and preferably close to the minimum value, which, according to the occasion, can either be disposed of or re-used until worn, and which is provided with an effective and reliable cutting edge such as that of a metal blade.